Motor

ABSTRACT

A motor includes a magnet rotating together with a rotor about a central axis, a substrate on which a sensor to detect a position of the magnet is installed, a housing to hold a stator to drive the rotor, a bearing assembly including a bearing holder, and a conductor assembly between the housing and the bearing assembly. The conductor assembly includes a conductor including a first conductor electrically connected to the sensor through the substrate and a conductor holder covering the conductor. The substrate is fixed to the conductor holder. In the radial direction, a gap is located between an outer side surface of the bearing holder and an inner side surface of the conductor holder, and at least a portion of the magnet is located in the gap.

CROSS REFERENCE TO RELATED APPLICATIONS

This is the U.S. national stage of PCT Application No.PCT/JP2018/000133, filed on Jan. 6, 2018, and priority under 35 U.S.C. §119(a) and 35 U.S.C. § 365(b) is claimed from Japanese Application No.2017-017758, filed Feb. 2, 2017; the entire disclosures of which areincorporated herein by reference.

1. FIELD OF THE INVENTION

The present disclosure relates to a motor.

2. BACKGROUND

With the miniaturization of a device, a demand for the miniaturizationof a motor mounted on the device is also increasing. When components ofthe motor are assembled, the components are often mounted in an axialdirection in an overlapping manner, so that dimensions in an axialdirection are likely to be large. Thus, for example, in a related art, asensor magnet configured to detect a rotational position of a rotor isinstalled in an outer side of a bearing support in a radial direction,and a position sensor is installed on an outer side surface of thebearing support, thereby suppressing an increase in dimensions of themotor in the axial direction. Further, in a related art, a Hallintegrated circuit (IC) formed on a front end plate and a sensor magnetinstalled on a magnet fixing member are disposed on an outer side in aradial direction of a bearing, which supports a shaft.

However, when the number of components of a motor increases, the numberof assembly processes increases so that the work efficiency is likely tobe lowered. In addition, when the components are arranged in a radialdirection, the structure of the motor is also complicated, so that theassembling is more likely to be difficult.

SUMMARY

An example embodiment of the present disclosure provides a motorincluding a rotor rotatable about a central axis extending in a verticaldirection, a stator facing the rotor in a radial direction to drive therotor, a housing to hold the stator, a bearing located on a positionhigher than the stator in an axial direction to rotatably support therotor, a bearing assembly including a bearing holder to hold thebearing, a magnet rotating together with the rotor, a sensor to detect aposition of the magnet, a substrate on which the sensor is installed,and a conductor assembly between the housing and the bearing assembly,wherein the conductor assembly includes a conductor, and a conductorholder covering the conductor, wherein the conductor includes a firstconductor electrically connected to the sensor through the substrate,the substrate is fixed to the conductor holder, in the radial direction,a gap is located between an outer side surface of the bearing holder andan inner side surface of the conductor holder, and at least a portion ofthe magnet is located in the gap.

The above and other elements, features, steps, characteristics andadvantages of the present disclosure will become more apparent from thefollowing detailed description of the example embodiments with referenceto the attached drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross-sectional view illustrating a configuration example ofa motor according to a first example embodiment of the presentdisclosure.

FIG. 2 is an enlarged cross-sectional view illustrating the arrangementof a magnet, a sensor, and a substrate according to a modified exampleof the first example embodiment of the present disclosure.

FIG. 3 is a cross-sectional view illustrating a configuration example ofa motor according to a second example embodiment of the presentdisclosure.

FIG. 4 is an enlarged cross-sectional view illustrating the arrangementof a magnet, a sensor, and a substrate according to a modified exampleof the second example embodiment of the present disclosure.

FIG. 5 is a cross-sectional view illustrating a configuration example ofa motor according to a third example embodiment of the presentdisclosure.

FIG. 6 is an enlarged cross-sectional view illustrating the arrangementof a magnet, a sensor, and a substrate according to a modified exampleof the third example embodiment of the present disclosure.

FIG. 7 is a cross-sectional view illustrating a configuration example ofa motor according to a fourth example embodiment of the presentdisclosure.

FIG. 8 is an enlarged cross-sectional view illustrating the arrangementof a magnet, a sensor, and a substrate according to a modified exampleof the fourth example embodiment of the present disclosure.

DETAILED DESCRIPTION

Example embodiments of the present disclosure will be described belowwith reference to the drawings.

Further, in the present specification, in a motor 100, a directionparallel to a central axis CA is referred to as an “axial direction”.Also, in the axial direction, a direction from a housing unit 110 towarda bearing assembly 130 is referred to as “upward”, and a direction fromthe bearing assembly 130 toward the housing unit 110 is referred to as“downward”. Also, in surfaces of each component, a surface facing upwardin the axial direction is referred to as an “upper surface”, and asurface facing downward in the axial direction is referred to as a“lower surface”.

Further, a direction orthogonal to the central axis CA is referred to asa “radial direction”, and a circumferential direction about the centralaxis CA is referred to as a “circumferential direction”. In addition, inthe radial direction, a direction toward the central axis CA is referredto as “inward”, and a direction away from the central axis CA isreferred to as “outward”. Also, in side surfaces of each component, aside surface facing inward in the radial direction is referred to as an“inner side surface”, and a side surface facing outward in the radialdirection is referred to as an “outer side surface”.

Further, designations of directions and surfaces described above do notindicate the positional relationship and direction in the case of beingincorporated into an actual device.

FIG. 1 is a cross-sectional view illustrating a configuration example ofa motor 100 according to a first example embodiment. In FIG. 1, themotor 100 is cut at a cut surface including a central axis CA. This alsoapplies to FIGS. 2 to 8 which are illustrated as other cross-sectionalviews to be described later. The motor 100 is an inner-rotor type asshown in FIG. 1 and includes a housing unit 110, a conductor assembly120, and a bearing assembly 130.

The housing unit 110 includes a stator 1 and a housing 112. Theconductor assembly 120 also includes a conductor 121, a conductor holder122, a substrate 123, a sensor 124, and O-rings 125 a and 125 b. Theconductor assembly 120 is sandwiched between the housing 112 and thebearing assembly 130 through the O-rings 125 a and 125 b. Further, thebearing assembly 130 includes a shaft 101, a rotor 102, a magnet holder103, a magnet 104 for a sensor, a first bearing 131, a second bearing132, and a bearing holder 133.

The shaft 101 is a rotating shaft rotatable about the central axis CAextending in a vertical direction and rotatably supported by the firstbearing 131 and the second bearing 132.

The rotor 102 is mounted on the shaft 101 and is rotatable with theshaft 101 about the central axis CA. The rotor 102 includes a magnet(not shown) for rotational driving, and faces an inner side surface ofthe stator 1 in a radial direction.

The magnet holder 103 is a ring-shaped member that supports the magnet104 for the sensor 124 and is mounted on the shaft 101 between the rotor102 and the second bearing 132. The magnet holder 103 and the magnet 104rotate together with the shaft 101 and the rotor 102. The magnet 104 forthe sensor 124 is an annular-shaped member in which an S-pole and anN-pole are alternately magnetized in a circumferential direction.

The stator 1 has an annular shape, faces the rotor 102 in the radialdirection, and drives the rotor 102. The stator 1 includes a stator core10, an insulator 11, and a plurality of coils 12.

The stator core 10 is an iron core member in which a plurality ofplate-shaped members each obtained by punching, for example, anelectromagnetic steel plate are laminated. The stator core 10 includes acore back having an annular shape and a plurality of teeth extendinginward in the radial direction from an inner side surface of the coreback. Each of the coils 12 is configured by winding a conducting wire 12a around each tooth through the insulator 11.

When a driving current is supplied to the coils 12, radial magnetic fluxis generated in the stator core 10. The stator 1 causes this magneticflux to magnetically act on magnetic flux of a magnet for rotationallydriving the rotor 102 to cause the rotor 102 to generate torque in thecircumferential direction. Thus, the rotor 102 rotates with the shaft101, the magnet 104 for a sensor, and the magnet for rotational drivingabout the central axis CA.

In addition, the stator 1 may further include an intermediate bus bar(not shown). The intermediate bus bar is installed on the insulator 11and electrically connected to the coils 12. A second conductor 121 b tobe described below is electrically connected to the coils 12 through theintermediate bus bar. In this manner, the coils 12 of the stator 1 maybe electrically connected to the second conductor 121 b on the stator 1side (that is, on a lower side in the axial direction) than theconductor assembly 120 in the axial direction. Thus, a gap S, which willbe described below, between the bearing holder 133 and the conductorassembly 120 may be easily secured.

The housing 112 holds the stator 1 and the first bearing 131. The firstbearing 131 is located on a position lower than the stator 1 in theaxial direction and rotatably supports the shaft 101 in a lower side inthe axial direction.

The conductor 121 includes a plurality of first conductors 121 a and aplurality of second conductors 121 b. Each of the first conductor 121 aand the second conductor 121 b includes a straight-shaped part (notshown) and an arc-shaped part (not shown) extending in thecircumferential direction from the straight-shaped part. The firstconductor 121 a is electrically connected to the substrate 123. Thesensor 124 is mounted on the substrate 123, and thus the first conductor121 a is electrically connected to the sensor 124 through the substrate123. The driving current is supplied to the stator 1 through the secondconductor 121 b. More specifically, the second conductor 121 b includesone end electrically connected to the conducting wire 12 a of theplurality of coils 12, and the other end connected to an external powersupply (not shown), thereby supplying the driving current to each of thecoils 12. The first conductor 121 a and the second conductor 121 b arebus bars made of a copper plate in the present example embodiment, butthe present disclosure is not limited to this example, and the firstconductor 121 a and the second conductor 121 b may be a wire made of ametal wire coated with, for example, an insulating member.

The conductor holder 122 is made of resin, covers the conductor 121, andholds the conductor 121. The conductor assembly 120 is an integrallymolded product of the conductor 121 and the conductor holder 122. Theconductor holder 122 includes an annular part 122 a and a connector part122 b. The annular part 122 a covers the arc-shaped part of the firstconductor 121 a and the arc-shaped part of the second conductor 121 b.The connector part 122 b covers the straight-shaped part of the firstconductor 121 a and the straight-shaped part of the second conductor 121b. Further, the connector part 122 b has a shape in which across-section thereof viewed from the circumferential direction is anL-shape, and is connected to the annular part 122 a in the radialdirection. That is, the annular part 122 a and the connector part 122 bare an integrally molded product. One end of each of the plurality offirst conductors 121 a is exposed through a lower surface of the annularpart 122 a. Further, although not illustrated in FIG. 1, one end of eachof the plurality of second conductors 121 b is exposed through an innerside surface of the annular part 122 a and electrically connected to theconducting wire 12 a withdrawn from the coil 12 upward in the axialdirection. One ends of the plurality of first conductors 121 a and theother ends of the second conductor 121 b are exposed through an end ofthe connector part 122 b, which extends in the axial direction. Thus,the conductor 121 and the conductor holder 122 may not be separatelymounted when assembling the motor 100, thereby reducing the number ofassembly processes of the motor 100.

The substrate 123 is, for example, a resin circuit board on whichelectronic components are mounted, and is fixed to the conductor holder122. More specifically, the substrate 123 has an arc shape correspondingto the annular part 122 a of the conductor assembly 120. In the radialdirection, the inner diameter of the substrate 123 is smaller than theinner diameter of the annular part 122 a, and the outer diameter of thesubstrate 123 is smaller than the outer diameter of the annular part 122a. The substrate 123 is in contact with and fixed to the lower surfaceof the annular part 122 a. Further, an inner peripheral edge of thesubstrate 123 in the radial direction is located inward in the radialdirection than the inner peripheral edge of the annular part 122 a.Thus, the sensor 124 mounted on an upper surface of the substrate 123 islocated inward in the radial direction than the annular part 122 a, andfaces an inner side surface of the annular part 122 a. The substrate 123is fixed by thermal welding in which a portion of the annular part 122 ais melted. The substrate 123 is electrically connected to the one end ofthe first conductor 121 a exposed through the lower surface of theannular part 122 a by soldering. Further, the substrate 123 is locatedat a position that does not interfere with a connection part between theone end of the first conductor 121 a and the conducting wire 12 awithdrawn from the coil 12.

In the first example embodiment, the substrate 123 is installed on thestator 1 side (that is, on a lower side in the axial direction) than theconductor holder 122 and the magnet 104 in the axial direction, and ismounted on a lower surface of the conductor holder 122. In this manner,when assembling the motor 100, for example, the housing unit 110, theconductor assembly 120, and the bearing assembly 130 are assembled. Thatis, first, the conductor assembly 120 is mounted on the housing unit110. Thereafter, the motor 100 is completed by mounting the bearingassembly 130. Thus, the assembly work of the motor 100 is facilitated byassembling individual parts into the units and then mounting the unitsto each other. Further, the assembling method is not limited thereto,and for example, the O-rings 125 a and 125 b may be mounted alonewithout being unitized into the conductor assembly 120.

The sensor 124 is, for example, a chip-type Hall device, and a pluralityof (for example, three) sensors 124 are installed on the substrate 123at intervals in the circumferential direction, and the sensor 124detects a rotational position of the magnet 104 rotating together withthe rotor 102. In the first example embodiment, the sensor 124 isinstalled on the upper surface of the substrate 123 and overlaps aportion of the trajectory of the rotating magnet 104 when viewed fromthe axial direction. More specifically, the sensor 124 faces the magnet104 in the axial direction. Thus, the size of the motor 100 in theradial direction may be suppressed to be increased as compared with thecase in which the sensor 124 faces a portion of the trajectory of therotating magnet 104 in the radial direction.

The second bearing 132 is located on a position higher than the stator 1in the axial direction and rotatably supports the rotor 102 in an upperside in the axial direction. More specifically, the second bearing 132rotatably supports the rotor 102 by rotatably supporting the shaft 101together with the first bearing 131.

The bearing holder 133 is mounted on an upper end of the conductorholder 122 in the axial direction through the O-ring 125 a. The bearingholder 133 includes an opening 133 a through which the shaft 101 isinserted when viewed from the axial direction, a holder 133 b holdingthe second bearing 132 on an outer side of the opening 133 a in theradial direction, and a cover 133 c covering an upper surface and anouter side surface of the conductor holder 122. The opening 133 a isinstalled at a central portion of the bearing holder 133. The cover 133c is installed on an outer side of the holder 133 b in the radialdirection.

Further, in the radial direction of the bearing holder 133, the holder133 b has a cylindrical shape fitted to an outer side surface of thesecond bearing 132, and is located on a position lower than the cover133 c in the axial direction. The outer diameter of the holder 133 b issufficiently smaller than the inner diameter of the conductor holder122. Thus, the gap S having an annular shape is formed between an outerside surface of the holder 133 b and an inner side surface of theconductor holder 122. More specifically, since the outer diameter of theholder 133 b is sufficiently smaller than the inner diameter of theannular part 122 a, the gap S is formed between the holder 133 b and theannular part 122 a. The gap S is a space formed by the outer sidesurface of the holder 133 b and the inner side surface of the conductorholder 122 facing each other in the radial direction. However, even whenthe length of the outer side surface of the holder 133 b and the lengthof the inner side surface of the conductor holder 122 differ from eachother in the axial direction, or the outer side surface of the holder133 b and the inner side surface of the conductor holder 122 haveunevenness, a space between the outer side surface of the holder 133 band the inner side surface of the conductor holder 122 facing each otherin the radial direction is referred to as the gap S. Further, thebearing holder 133 is formed by punching a single metal plate, but thepresent disclosure is not limited to such a method, and the same shapemay be formed by another processing method, or the bearing holder 133may be configured by mounting a plurality of parts.

In the first example embodiment, as shown in FIG. 1, a portion of themagnet 104 is located in the gap S. Further, the present disclosure isnot limited to this example, and the entire magnet 104 may be located inthe gap S. Since at least a portion of the magnet 104 is located in thegap S, an increase in size of the motor 100 in the axial direction maybe suppressed, and the enlargement of the motor 100 may be suppressed.That is, the example embodiment may contribute to the miniaturization ofthe motor 100.

Further, when the substrate 123 is mounted on the conductor holder 122,the position of the substrate 123 may be determined by bringing thesubstrate 123 into contact with the conductor holder 122. In addition,one end of the first conductor 121 a is exposed on the contact surface,so that the first conductor 121 a may be easily brought into contactwith a conductive part (for example, a wiring pattern) of the substrate123. The connection of the conductive part and the first conductor 121 amay be performed, for example, by soldering or press-fit bonding.Further, the substrate 123 may be fixed by thermal welding by mountingthe substrate 123 on the conductor holder 122 made of resin. However,the present disclosure is not limited to such a method, and anotherfixing method such as snap fitting may also be applied for the fixing ofthe substrate 123. Thus, the first conductor 121 a and the sensor 124may be easily electrically connected to each other.

In the above-described first example embodiment, the substrate 123 andthe sensor 124 are located outside the gap S as shown in FIG. 1, but thepresent disclosure is not limited to this example, the substrate 123 andthe sensor 124 may be located inside the gap S. FIG. 2 is an enlargedcross-sectional view illustrating the arrangement of a magnet 104, asensor 124, and a substrate 123 according to a modified example of thefirst example embodiment. Further, FIG. 2 corresponds to the structureof a range enclosed by a broken line in FIG. 1.

In the modified example, the substrate 123 is located in a gap S betweena bearing holder 133 and a conductor holder 122 as illustrated in FIG.2. Further, a notch 122 c having an arc shape and extending in acircumferential direction is formed on a lower surface of an annularpart 122 a of the conductor holder 122. The notch 122 c is formed bynotching a region including an inner peripheral edge in a radialdirection of the lower surface of the annular part 122 a in an axialdirection toward an upper side of the region. The substrate 123 and thesensor 124 are located inside the gap S by mounting the substrate 123 onthe notch 122 c. A magnet 104 is located upward in the gap S in theaxial direction by extending an outer peripheral side of a magnet holder103 upward in the axial direction. Thus, not only the magnet 104 butalso the substrate 123 and the sensor 124 may be located inside the gapS. In this manner, in the first example embodiment (see FIG. 1), aportion of the magnet 104, the substrate 123, and the sensor 124 arepushed downward in the axial direction from the gap S, but the space,into which a portion of the magnet 104, the substrate 123, and thesensor 124 are pushed, in the first example embodiment may be reduced bythe configuration of the modified example. Thus, the motor 100 may beminiaturized, and in particular, the size in the axial direction may beminiaturized. Further, a coil 12 and the substrate 123 are furtherspaced apart from each other, and thus electrical insulationtherebetween is easy to achieve. In addition, the work of connecting aconducting wire 12 a withdrawn from the coil 12 to one end of a firstconductor 121 a is facilitated.

In the modified example, the entire sensor 124 is located in the gap Sas shown in FIG. 2. In addition, the present disclosure is not limitedto this example, a portion of the sensor 124 may be located in the gapS. Since at least a portion of the sensor 124 is located in the gap S,an increase in size of the motor 100 in the axial direction may besuppressed, and the enlargement of the motor 100 may be suppressed. Inparticular, the size of the motor 100 in the axial direction may bereduced. That is, the modified example may contribute to theminiaturization of the motor 100.

Next, a second example embodiment will be described. Configurations ofthe second example embodiment, which are different from the firstexample embodiment and the modified example thereof, will be describedbelow. In addition, the same configurations as those in the firstexample embodiment and the modified example thereof may be denoted bythe same reference numerals and descriptions thereof may be omitted.

FIG. 3 is a cross-sectional view illustrating a configuration example ofa motor 100 according to a second example embodiment.

In the second example embodiment, a sensor 124 is a lead-type Halldevice and is mounted on an upper surface of a substrate 123 as shown inFIG. 3. The sensor 124 overlaps a portion of the trajectory of arotating magnet 104 in a radial direction. More specifically, the sensor124 faces the magnet 104 in the radial direction. Further, in FIG. 3, anotch 122 c which is notched outward in the radial direction to theextent that a plurality of sensors 124 may be accommodated is formed onan inner side surface of an annular part 122 a of a conductor holder122. Thus, a gap S is enlarged according to the size of the notch 122 c.Thus, a portion of the sensor 124 is located in the gap S. However, thepresent disclosure is not limited to this example, and the entire sensor124 may be located in the gap S.

The substrate 123 is installed on a stator 1 side (that is, on a lowerside in an axial direction) than the conductor holder 122 and the magnet104 in the axial direction, and is mounted on a lower surface of theconductor holder 122.

In the second example embodiment described above, the substrate 123 islocated outside the gap S as shown in FIG. 3, but the present disclosureis not limited to this example, and the substrate 123 may be locatedinside the gap S. FIG. 4 is an enlarged cross-sectional viewillustrating the arrangement of a magnet 104, a sensor 124, and asubstrate 123 according to a modified example of the second exampleembodiment. Further, FIG. 4 corresponds to the structure of a rangeenclosed by a broken line in FIG. 3.

In the modified example, the substrate 123 is located in a gap S betweena bearing holder 133 and a conductor holder 122 as illustrated in FIG.4. Further, a notch 122 c having an arc shape and extending in acircumferential direction is formed on a lower surface of an annularpart 122 a of the conductor holder 122. The notch 122 c is formed bynotching a region including an inner peripheral edge in a radialdirection of the lower surface of the annular part 122 a in an axialdirection toward an upper side of the region. The substrate 123 and thesensor 124 are located inside the gap S by mounting the substrate 123 onthe notch 122 c. A magnet 104 is located upward in the gap S in theaxial direction by extending an outer peripheral side of a magnet holder103 upward in the axial direction. Thus, not only the magnet 104 butalso the substrate 123 and the sensor 124 may be located inside the gapS. In the second example embodiment (see FIG. 3), a portion of themagnet 104, the substrate 123, and a portion of the sensor 124 arepushed downward in the axial direction from the gap S, but the space,into which a portion of the magnet 104, the substrate 123, and a portionof the sensor 124 are pushed, in the second example embodiment may bereduced by the configuration of the modified example. Thus, the motor100 may be miniaturized, and in particular, the size in the axialdirection may be miniaturized. Further, a coil 12 and the substrate 123are further spaced apart from each other, and thus electrical insulationtherebetween is easy to achieve. In addition, the work of connecting aconducting wire 12 a withdrawn from the coil 12 to one end of a firstconductor 121 a is facilitated.

Next, a third example embodiment will be described. Configurations ofthe third example embodiment, which are different from the first andsecond example embodiments and the modified examples thereof, will bedescribed below. In addition, the same configurations as those in thefirst and second example embodiments and the modified examples thereofmay be denoted by the same reference numerals and descriptions thereofmay be omitted.

FIG. 5 is a cross-sectional view illustrating a configuration example ofa motor 100 according to a third example embodiment.

In the third example embodiment, as shown in FIG. 5, a sensor 124 is alead-type Hall device, is installed on a lower surface of a substrate123, and overlaps a portion of the trajectory of a rotating magnet 104in a radial direction. More specifically, the sensor 124 faces themagnet 104 in the radial direction.

The substrate 123 is located in a gap S, is installed on an oppositeside of a stator 1 (that is, on an upper side in an axial direction)than a conductor holder 122 and the magnet 104 in the axial direction,and is mounted on an upper surface of the conductor holder 122. Morespecifically, the substrate 123 is installed on an upper surface of anannular part 122 a of the conductor holder 122 and mounted on a notch122 c having an annular shape and extending in a circumferentialdirection. The notch 122 c is formed by notching a region including aninner peripheral edge in the radial direction of the upper surface ofthe annular part 122 a in the axial direction toward a lower side of theregion. The substrate 123 and the sensor 124 are located inside the gapS by mounting the substrate 123 on the notch 122 c.

Further, in the assembly of the motor 100 of the present exampleembodiment,

first, a bearing assembly 130 from which a second bearing 132 and abearing holder 133 are omitted is mounted on a housing unit 110.Thereafter, the conductor holder 122 is mounted together with O-rings125 a and 125 b. Thereafter, the motor 100 is completed by mounting thesecond bearing 132 and the bearing holder 133.

Further, the present disclosure is not limited to the example describedwith reference to FIG. 5, and in the third example embodiment, thesubstrate 123 may be installed on a position lower than the magnet 104in the axial direction. FIG. 6 is an enlarged cross-sectional viewillustrating the arrangement of a magnet 104, a sensor 124, and asubstrate 123 according to a modified example of the third exampleembodiment. Further, FIG. 6 corresponds to the structure of a rangeenclosed by a broken line in FIG. 5.

In the modified example, the substrate 123 located in a gap S isprovided closer to a stator 1 than the magnet 104 in an axial directionas shown in FIG. 6. Further, the sensor 124 facing the magnet 104 in aradial direction is installed on an upper surface of the substrate 123.More specifically, the substrate 123 is installed on an upper surface ofan annular part 122 a of a conductor holder 122 and mounted on a notch122 c having an annular shape and extending in a circumferentialdirection. The notch 122 c is formed by cutting out a region includingan inner peripheral edge in a radial direction of the upper surface ofthe annular part 122 a in the axial direction toward a lower side of theregion. The substrate 123 and the sensor 124 are located inside the gapS by mounting the substrate 123 on the notch 122 c. In this manner, forexample, a housing unit 110, a conductor assembly 120, and a bearingassembly 130 may be assembled in this order in the axial direction as inthe first example embodiment. Thus, the assembly work of the motor 100is facilitated.

Next, a fourth example embodiment will be described. Configurations ofthe fourth example embodiment, which are different from the first tothird example embodiments and the modified examples thereof, will bedescribed below. In addition, the same configurations as those in thefirst to third example embodiments and the modified examples thereof maybe denoted by the same reference numerals and descriptions thereof maybe omitted.

FIG. 7 is a cross-sectional view illustrating a configuration example ofa motor 100 according to the fourth example embodiment. In the fourthexample embodiment, as shown in FIG. 7, a sensor 124 is a chip-type Halldevice, is installed on a lower surface of a substrate 123, is locatedon a position higher than a magnet 104 in an axial direction, andoverlaps a portion of the trajectory of the rotating magnet 104 in theaxial direction. More specifically, the sensor 124 faces the magnet 104in the axial direction. In this manner, an increase in size of the motor100 in a radial direction may be suppressed.

The substrate 123 is installed on an opposite side of the stator 1 (thatis, on an upper side in the axial direction) than a conductor holder 122and the magnet 104 in the axial direction, and is mounted on an uppersurface of the conductor holder 122. More specifically, the substrate123 is installed on an upper surface of an annular part 122 a of theconductor holder 122 and mounted on a notch 122 c having an annularshape and extending in a circumferential direction. The notch 122 c isformed by notching a region including an inner peripheral edge in aradial direction of the upper surface of the annular part 122 a in theaxial direction toward a lower side of the region. The substrate 123 andthe sensor 124 are located inside a gap S by mounting the substrate 123on the notch 122 c.

Further, the present disclosure is not limited to the example describedwith reference to FIG. 7, and in the fourth example embodiment, thesubstrate 123 and the sensor 124 may be installed on a position lowerthan the magnet 104 in the axial direction. FIG. 8 is an enlargedcross-sectional view illustrating the arrangement of a magnet 104, asensor 124, and a substrate 123 according to a modified example of thefourth example embodiment. Further, FIG. 8 corresponds to the structureof a range enclosed by a broken line in FIG. 7.

In the modified example, the substrate 123 and the sensor 124 located ina gap S are provided closer to a stator 1 than the magnet 104 in anaxial direction as shown in FIG. 8. Further, the sensor 124 facing themagnet 104 in the axial direction is installed on an upper surface ofthe substrate 123. More specifically, the substrate 123 is installed onan upper surface of an annular part 122 a of a conductor holder 122 andmounted on a notch 122 c having an annular shape and extending in acircumferential direction. The notch 122 c is formed by notching aregion including an inner peripheral edge of the upper surface of theannular part 122 a in the axial direction toward a lower side of theregion in a radial direction. The substrate 123 and the sensor 124 arelocated inside the gap S by mounting the substrate 123 on the notch 122c. In this manner, for example, a housing unit 110, a conductor assembly120, and a bearing assembly 130 may be assembled in this order in theaxial direction. Thus, the assembly work of the motor 100 isfacilitated.

The motor 100 described in each of the above-described exampleembodiments includes a rotor 102 rotatable about a central axis CAextending in the vertical direction, a stator 1 facing the rotor 102 inthe radial direction and driving the rotor 102, a housing 112 configuredto hold the stator 1, a second bearing 132 located on a position higherthan stator 1 in the axial direction and rotatably supporting the rotor102, a bearing assembly 130 having a bearing holder 133 holding thesecond bearing 132, a magnet 104 rotating together with the rotor 102, asensor 124 configured to detect the position of the magnet 104, asubstrate 123 on which the sensor 124 is installed, a conductor assembly120 sandwiched between the housing 112 and the bearing assembly 130. Theconductor assembly 120 includes a conductor 121 and a conductor holder122 covering the conductor 121. The conductor 121 includes a firstconductor 121 a electrically connected to the sensor 124 through thesubstrate 123. The substrate 123 is fixed to the conductor holder 122.In the radial direction, a gap S is formed between an outer side surfaceof the bearing holder 133 and an inner side surface of the conductorholder 122, and at least a portion of the magnet 104 is located in thegap S. Further, the first conductor 121 a is a bus bar or a conductingwire.

According to the above-described configuration, the electricalconnection between the sensor 124 and the first conductor 121 (forexample, a bus bar or a conducting wire) may be facilitated by fixingthe substrate 123 on which the sensor 124 is installed to the conductorholder 122. Further, the substrate 123 and the sensor 124 may also bemounted by mounting the conductor assembly 120 when the motor 100 isassembled. Thus, the motor 100 may be easily assembled, and thus thework efficiency of the assembly process of the motor 100 may beimproved.

In addition, since at least a portion of the magnet 104 for the sensor124 is located in the gap S between the bearing holder 133 and theconductor holder 122, the enlargement of the motor 100 may besuppressed, and in particular, the dimension of the motor 100 in theaxial direction may be reduced.

The example embodiments of the present disclosure have been describedabove. The scope of the present disclosure is not limited to theabove-described example embodiments. The present disclosure may beimplemented with various modifications without departing from the scopeof the disclosure. Further, the items described in the above-describedexample embodiments may be arbitrarily combined within a range in whichinconsistency does not occur.

The present disclosure is useful for a motor, for example, having a gapS further outward than a bearing holder in a radial direction.

Features of the above-described example embodiments and themodifications thereof may be combined appropriately as long as noconflict arises.

While example embodiments of the present disclosure have been describedabove, it is to be understood that variations and modifications will beapparent to those skilled in the art without departing from the scopeand spirit of the present disclosure. The scope of the presentdisclosure, therefore, is to be determined solely by the followingclaims.

1-12. (canceled)
 13. A motor comprising: a rotor rotatable about a central axis extending in a vertical direction; a stator facing the rotor in a radial direction to drive the rotor; a housing to hold the stator; a bearing located on a position higher than the stator in an axial direction to rotatably support the rotor; a bearing assembly including a bearing holder to hold the bearing; a magnet to rotate together with the rotor; a sensor to detect a position of the magnet; a substrate on which the sensor is located; and a conductor assembly between the housing and the bearing assembly; wherein the conductor assembly includes a conductor, and a conductor holder covering the conductor; the conductor includes a first conductor electrically connected to the sensor through the substrate, the substrate is fixed to the conductor holder, in the radial direction, a gap is located between an outer side surface of the bearing holder and an inner side surface of the conductor holder, and at least a portion of the magnet is located in the gap.
 14. The motor of claim 13, wherein the first conductor includes a bus bar.
 15. The motor of claim 13, wherein the substrate is closer to the stator than the magnet in the axial direction.
 16. The motor of claim 13, wherein the substrate is located in the gap.
 17. The motor of claim 13, wherein at least a portion of the sensor is located in the gap.
 18. The motor of claim 13, wherein the substrate is closer to the stator than the conductor holder in the axial direction, and the sensor overlaps a portion of a trajectory of the rotating magnet when viewed in the axial direction.
 19. The motor of claim 13, wherein the substrate is closer to the stator than the conductor holder in the axial direction, and the sensor overlaps a portion of a trajectory of the rotating magnet in the radial direction.
 20. The motor of claim 13, wherein the substrate is located on an opposite side of the stator than the conductor holder in the axial direction, and the sensor overlaps a portion of a trajectory of the rotating magnet in the radial direction.
 21. The motor of claim 13, wherein the substrate is located on an opposite side of the stator than the conductor holder in the axial direction, and the sensor overlaps a portion of a trajectory of the rotating magnet when viewed in the axial direction.
 22. The motor of claim 13, wherein the conductor assembly is an integrally molded product including the conductor and the conductor holder.
 23. The motor of claim 13, wherein the conductor further includes a second conductor through which a driving current supplied to the stator.
 24. The motor of claim 23, wherein the stator includes a coil provided on a stator core through an insulator, and an intermediate bus bar provided on the insulator and electrically connected to the coil; and the second conductor is electrically connected to the coil through the intermediate bus bar. 